Stereoregular diene polymers are produced and used industrially on a large scale as an important component of tire compounds. Diene polymers with high levels of stereoregularity are almost exclusively prepared with coordination polymerization catalysts, which are in general easily poisoned by polar functionalities. Because of this poisoning effect, the types of monomers that are compatible with coordination catalysts are usually limited to simple hydrocarbons. It is well known within the tire industry that the incorporation of even low levels of functionality into certain tire polymers (prepared through anionic or emulsion polymerization) significantly improves the performance of tires containing such polymers. Unfortunately, there is currently no reliable method to apply this functionalization technology to stereoregular diene polymers, but it is likely that such a polymer would show superior tire properties over known unfunctionalized polymers.
WO2004/007602 discloses a catalyst for the polymerization of 1,4-dienes, styrene and for the copolymerization of two monomers. The characteristics of the inventive catalyst include a high degree of stereoselectivity, catalytic activity and tolerance to the presence of polar impurities. Said catalyst combines the characteristics specific to Ni-based diene polymerization catalysts (high stereoselectivity and catalytic activity) with a well-defined character and tolerance to the presence of polar substances.
O'Connor et al. (Journal of Applied Polymer Science, Part A: Polymer Chemistry, Vol. 48, 1901-1912 (2010)) disclose polymerization of 2,3 bis(4-trifluoroethoxy-4-oxobutyl)-1,3-butadiene catalyzed by a cationic ally (Ni)II complex. Attempts to polymerize the monomer with the ester groups replaced by more basic amino and hydroxy functional groups were unsuccessful.
U.S. Pat. No. 6,627,721 discloses functionalized elastomers made by anionic polymerization of diene monomer and a functional vinyl aromatic monomer having a nitrogen-containing group.
U.S. Pat. Nos. 6,100,373; 6,344,538; and 6,583,260 disclose functionalized diene monomers and polymers containing functionalized dienes and methods for their preparation.